magneto-optic storage
magneto-optic storage (M-O storage) A storage method, used in rewritable optical disk drives, that combines magnetic and optical recording techniques. The disk is coated with film that initially is uniformly magnetized. A laser beam is used to demagnetize a small spot on the film by heating it above a critical temperature (the Curie point or compensation point), and a local magnetic field determines the direction in which the spot is magnetized when it cools. To read the information, the disk is scanned by polarized light from a low-power laser. The plane of polarization of the light reflected from a magnetized surface is rotated according to the direction of the magnetic field – the Kerr effect. This rotation, though small, can be detected and the original binary signal can be reproduced. In early M-O disk drives data had to be erased separately (usually during the previous revolution of the disk) before it could be rewritten, but direct rewriting is now possible.
The M-O technique achieves recording densities similar to those of other optical stores and much higher than has been achieved by magnetic recording. M-O media compete with dye-polymer media in the rewritable disk field. Dye-polymer media are in principle cheaper to make and need a simpler drive, but successful M-O media were produced some years before comparable dye-polymer media.
The M-O technique achieves recording densities similar to those of other optical stores and much higher than has been achieved by magnetic recording. M-O media compete with dye-polymer media in the rewritable disk field. Dye-polymer media are in principle cheaper to make and need a simpler drive, but successful M-O media were produced some years before comparable dye-polymer media.
More From encyclopedia.com
Optical Disk , optical disk A type of optical storage in which the medium is in the form of a disk that is rotated to give one dimension of access while the light b… Floppy Disk , Background
A floppy disk is a portable computer storage device that permits easy handling of data. Commonly used with personal computers, notebook co… Willis Obrien , Willis O'Brien
The father of "stop-motion" animation, Willis O'Brien (1886-1962) was a Hollywood special effects innovator most famous for his work u… Magnetic Disk , magnetic disk A rotatable storage medium usually in the form of a circular nonmagnetic rigid plate coated on both sides with magnetic material, follo… Otitis Media , Definition
Otitis media is an infection of the middle ear, which is located behind the eardrum. There are two main types of otitis media. In the firs… Homeotherm , ho·me·o·therm / ˈhōmēəˌ[unvoicedth]ərm/ (also ho·moi·o·therm) • n. Zool. an organism that maintains its body temperature at a constant level, usually…
You Might Also Like
NEARBY TERMS
magneto-optic storage